CMF / CRF Details

CMF ID: 7713

Install automated section speed enforcement system

Description: Installation of automated speed enforcement system. Determines average speed of vehicle over a long distance.

Prior Condition:  No Point-to-Point Automated Section Speed Enforcement System

Category: Advanced technology and ITS

Study: Effects on Speed and Safety of Point-to-Point Speed Enforcement Systems: Evaluation on the Urban Motorway A56 Tangenziale di Napoli, Montella, et al., 2005

Image: View the countermeasure image.

 
Star Quality Rating:4 Stars  [View score details]
Rating Points Total:120
Crash Modification Factor (CMF)
Value:0.512
Adjusted Standard Error:
Unadjusted Standard Error:0.05
Crash Reduction Factor (CRF)
Value:48.8  (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:5
Applicability
Crash Type:All
Crash Severity:All
Roadway Types:Principal Arterial Other Freeways and Expressways
Street Type:
Minimum Number of Lanes:6
Maximum Number of Lanes:6
Number of Lanes Direction:
Number of Lanes Comment:
Crash Weather:Not specified
Road Division Type:Divided by Median
Minimum Speed Limit:80
Maximum Speed Limit:80
Speed Unit:km/h
Speed Limit Comment:
Area Type:Urban
Traffic Volume:
Average Traffic Volume:
Time of Day:All
If countermeasure is intersection-based
Intersection Type:
Intersection Geometry:
Traffic Control:
Major Road Traffic Volume:
Minor Road Traffic Volume:
Average Major Road Volume :
Average Minor Road Volume :
Development Details
Date Range of Data Used:2006 to 2011
Municipality:Naples
State:notusa
Country:Italy
Type of Methodology Used:Before/after using empirical Bayes or full Bayes
Sample Size (crashes):345 crashes before, 130 crashes after
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Mar 08, 2016
Comments:CMFs of total crashes on horizontal curves, with radius varying between 200 and 3000 meters. The authors note that crash reduction effects decreased over time and speed, speed variability, and non-compliance to speed limits significantly increased over time.